scholarly journals Insight into the Evolution of Magnetotaxis in Magnetospirillum spp., Based onmamGene Phylogeny

2012 ◽  
Vol 78 (20) ◽  
pp. 7238-7248 ◽  
Author(s):  
Christopher T. Lefèvre ◽  
Marian L. Schmidt ◽  
Nathan Viloria ◽  
Denis Trubitsyn ◽  
Dirk Schüler ◽  
...  
Keyword(s):  
16S Rrna ◽  
New Genus ◽  
Common Ancestor ◽  
Rrna Gene ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
Bisphosphate Carboxylase ◽  
Content Type ◽  
Axenic Cultures ◽  
Insight Into

ABSTRACTVibrioid- to helical-shaped magnetotactic bacteria phylogenetically related to the genusMagnetospirillumwere isolated in axenic cultures from a number of freshwater and brackish environments located in the southwestern United States. Based on 16S rRNA gene sequences, most of the new isolates represent newMagnetospirillumspecies or new strains of knownMagnetospirillumspecies, while one isolate appears to represent a new genus basal toMagnetospirillum. Partial sequences of conservedmamgenes, genes reported to be involved in the magnetosome and magnetosome chain formation, and form II of the ribulose-1,5-bisphosphate carboxylase/oxygenase gene (cbbM) were determined in the new isolates and compared. ThecbbMgene was chosen for comparison because it is not involved in magnetosome synthesis; it is highly conserved and is present in all but possibly one of the genomes of the magnetospirilla and the new isolates. Phylogenies based on 16S rRNA,cbbM, andmamgene sequences were reasonably congruent, indicating that the genes involved in magnetotaxis were acquired by a common ancestor of theMagnetospirillumclade. However, in one case, magnetosome genes might have been acquired through horizontal gene transfer. Our results also extend the known diversity of theMagnetospirillumgroup and show that they are widespread in freshwater environments.

Reclassification of Parvularcula flava as Aquisalinus luteolus nom. nov. and emended description of the genus Aquisalinus

2021 ◽  
Vol 71 (10) ◽  
Author(s):  
Jun-Jie Ying ◽  
Zhi-Cheng Wu ◽  
Yuan-Chun Fang ◽  
Lin Xu ◽  
Cong Sun
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Type Species ◽  
Comparative Genomic ◽  
Rrna Gene ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
Content Type ◽  
Link Type ◽  
Type Strains

Parvularcula flava was proposed as a novel member of genus Parvularcula in 2016. Some time earlier, Aquisalinus flavus has been proposed as a novel species of a novel genus named Aquisalinus . When comparing the 16S rRNA gene sequences of type strains P. flava NH6-79T and A. flavus D11M-2T, they showed 97.9 % sequence identity, much higher than the sequence identities 92.7–94.3 % between P. flava NH6-79T and type strains in the genus Parvularcula , indicating that the later proposed novel taxon Parvularcula flava need reclassification. The phylogenetic trees based on 16S rRNA gene sequences and genome sequences both showed that P. flava NH6-79T and A. flavus D11M-2T formed a separated branch away from strains in the genera Parvularcula , Marinicaulis and Amphiplicatus . The average amino acid identity and average nucleotide identity values of P. flava NH6-79T and A. flavus D11M-2T were 87.9 and 85.0 %, respectively, much higher than the values between P. flava NH6-79T and other closely related type strains (54.3 %–58.1 % and 68.6–70.4 %, respectively). P. flava NH6-79T and A. flavus D11M-2T also contained summed feature 8 (C18 : 1  ω6c and/or C18 : 1  ω7c) and C16 : 0 as major fatty acids, distinguishing them from other closely related taxa. Based on the results of the phylogenetic, comparative genomic and phenotypic analyses, Parvularcula flava should be reclassified as Aquisalinus luteolus nom. nov. and the description of genus Aquisalinus is emended.

scholarly journals Molecular Characterization of anEndozoicomonas-Like Organism Causing Infection in the King Scallop (Pecten maximusL.)

2017 ◽  
Vol 84 (3) ◽  
Author(s):  
Irene Cano ◽  
Ronny van Aerle ◽  
Stuart Ross ◽  
David W. Verner-Jeffreys ◽  
Richard K. Paley ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Molecular Characterization ◽  
Mass Mortality ◽  
Rrna Gene ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
Content Type ◽  
The 16S Rrna Gene

ABSTRACTOne of the fastest growing fisheries in the UK is the king scallop (Pecten maximusL.), also currently rated as the second most valuable fishery. Mass mortality events in scallops have been reported worldwide, often with the causative agent(s) remaining uncharacterized. In May 2013 and 2014, two mass mortality events affecting king scallops were recorded in the Lyme Bay marine protected area (MPA) in Southwest England. Histopathological examination showed gill epithelial tissues infected with intracellular microcolonies (IMCs) of bacteria resemblingRickettsia-like organisms (RLOs), often with bacteria released in vascular spaces. Large colonies were associated with cellular and tissue disruption of the gills. Ultrastructural examination confirmed the intracellular location of these organisms in affected epithelial cells. The 16S rRNA gene sequences of the putative IMCs obtained from infected king scallop gill samples, collected from both mortality events, were identical and had a 99.4% identity to 16S rRNA gene sequences obtained from “CandidatusEndonucleobacter bathymodioli” and 95% withEndozoicomonasspecies.In situhybridization assays using 16S rRNA gene probes confirmed the presence of the sequenced IMC gene in the gill tissues. Additional DNA sequences of the bacterium were obtained using high-throughput (Illumina) sequencing, and bioinformatic analysis identified over 1,000 genes with high similarity to protein sequences fromEndozoicomonasspp. (ranging from 77 to 87% identity). Specific PCR assays were developed and applied to screen for the presence of IMC 16S rRNA gene sequences in king scallop gill tissues collected at the Lyme Bay MPA during 2015 and 2016. There was 100% prevalence of the IMCs in these gill tissues, and the 16S rRNA gene sequences identified were identical to the sequence found during the previous mortality event.IMPORTANCEMolluscan mass mortalities associated with IMCs have been reported worldwide for many years; however, apart from histological and ultrastructural characterization, characterization of the etiological agents is limited. In the present work, we provide detailed molecular characterization of anEndozoicomonas-like organism (ELO) associated with an important commercial scallop species.

scholarly journals ‘Candidatus Phytoplasma palmicola’, associated with a lethal yellowing-type disease of coconut (Cocos nucifera L.) in Mozambique

2014 ◽  
Vol 64 (Pt_6) ◽  
pp. 1890-1899 ◽  
Author(s):  
Nigel A. Harrison ◽  
Robert E. Davis ◽  
Carlos Oropeza ◽  
Ericka E. Helmick ◽  
María Narváez ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Cocos Nucifera ◽  
Rrna Gene ◽  
Similarity Coefficients ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
Content Type ◽  
Lethal Yellowing ◽  
The 16S Rrna Gene

In this study, the taxonomic position and group classification of the phytoplasma associated with a lethal yellowing-type disease (LYD) of coconut (Cocos nucifera L.) in Mozambique were addressed. Pairwise similarity values based on alignment of nearly full-length 16S rRNA gene sequences (1530 bp) revealed that the Mozambique coconut phytoplasma (LYDM) shared 100 % identity with a comparable sequence derived from a phytoplasma strain (LDN) responsible for Awka wilt disease of coconut in Nigeria, and shared 99.0–99.6 % identity with 16S rRNA gene sequences from strains associated with Cape St Paul wilt (CSPW) disease of coconut in Ghana and Côte d’Ivoire. Similarity scores further determined that the 16S rRNA gene of the LYDM phytoplasma shared <97.5 % sequence identity with all previously described members of ‘Candidatus Phytoplasma ’. The presence of unique regions in the 16S rRNA gene sequence distinguished the LYDM phytoplasma from all currently described members of ‘Candidatus Phytoplasma ’, justifying its recognition as the reference strain of a novel taxon, ‘Candidatus Phytoplasma palmicola’. Virtual RFLP profiles of the F2n/R2 portion (1251 bp) of the 16S rRNA gene and pattern similarity coefficients delineated coconut LYDM phytoplasma strains from Mozambique as novel members of established group 16SrXXII, subgroup A (16SrXXII-A). Similarity coefficients of 0.97 were obtained for comparisons between subgroup 16SrXXII-A strains and CSPW phytoplasmas from Ghana and Côte d’Ivoire. On this basis, the CSPW phytoplasma strains were designated members of a novel subgroup, 16SrXXII-B.

Sphingobium fontiphilum sp. nov., isolated from a freshwater spring

2013 ◽  
Vol 63 (Pt_5) ◽  
pp. 1906-1911 ◽  
Author(s):  
Shih-Yi Sheu ◽  
Yu-Wen Shiau ◽  
Yan-Ting Wei ◽  
Wen-Ming Chen
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Type Species ◽  
Phylogenetic Analyses ◽  
Rrna Gene ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
Phenotypic Data ◽  
Content Type ◽  
Link Type

To investigate the biodiversity of bacteria in the spring water of the Chengcing Lake Park in Taiwan, a Gram-stain-negative, rod-shaped, non-motile, non-spore-forming and aerobic bacterial strain, designated strain Chen16-4T, was isolated and characterized in a taxonomic study using a polyphasic approach. Phylogenetic analyses based on 16S rRNA gene sequences showed that the closest relatives of strain Chen16-4T were Sphingobium amiense YTT, Sphingobium yanoikuyae GIFU 9882T and Sphingobium scionense WP01T, with sequence similarities of 97.6, 97.1 and 97.0 %, respectively. A phylogenetic tree obtained with 16S rRNA gene sequences indicated that strain Chen16-4T and these three closest relatives formed an independent phylogenetic clade within the genus Sphingobium . The polar lipid pattern, the presence of spermidine and ubiquinone Q-10, the predominance of C18 : 1ω7c in the cellular fatty acid profile and the DNA G+C content also supported affiliation of the isolate to the genus Sphingobium . The DNA–DNA relatedness of strain Chen16-4T with respect to recognized species of the genus Sphingobium was less than 70 %. On the basis of the genotypic, chemotaxonomic and phenotypic data, strain Chen16-4T represents a novel species in the genus Sphingobium , for which the name Sphingobium fontiphilum sp. nov. is proposed. The type strain is Chen16-4T ( = BCRC 80308T = LMG 26342T = KCTC 23559T).

Evaluation of the DNA-dependent RNA polymerase β-subunit gene (rpoB) for phytoplasma classification and phylogeny

2013 ◽  
Vol 63 (Pt_10) ◽  
pp. 3904-3914 ◽  
Author(s):  
Deividas Valiunas ◽  
Rasa Jomantiene ◽  
Robert Edward Davis
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Rna Polymerase ◽  
Rrna Gene ◽  
Β Subunit ◽  
Subunit Gene ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
Content Type ◽  
Phytoplasma Classification

Phytoplasmas are classified into 16Sr groups and subgroups and ‘Candidatus Phytoplasma ’ species, largely or entirely based on analysis of 16S rRNA gene sequences. Yet, distinctions among closely related ‘Ca. Phytoplasma ’ species and strains based on 16S rRNA genes alone have limitations imposed by the high degree of rRNA nucleotide sequence conservation across diverse phytoplasma lineages and by the presence in a phytoplasma genome of two, sometimes sequence-heterogeneous, copies of the 16S rRNA gene. Since the DNA-dependent RNA polymerase (DpRp) β-subunit gene (rpoB) exists as a single copy in the phytoplasma genome, we explored the use of rpoB for phytoplasma classification and phylogenetic analysis. We sequenced a clover phyllody (CPh) phytoplasma genetic locus containing ribosomal protein genes, a complete rpoB gene and a partial rpoC gene encoding the β′-subunit of DpRp. Primers and reaction conditions were designed for PCR-mediated amplification of rpoB gene fragments from diverse phytoplasmas. The rpoB gene sequences from phytoplasmas classified in groups 16SrI, 16SrII, 16SrIII, 16SrX and 16SrXII were subjected to sequence similarity and phylogenetic analyses. The rpoB gene sequences were more variable than 16S rRNA gene sequences, more clearly distinguishing among phytoplasma lineages. Phylogenetic trees based on 16S rRNA and rpoB gene sequences had similar topologies, and branch lengths in the rpoB tree facilitated distinctions among closely related phytoplasmas. Virtual RFLP analysis of rpoB gene sequences also improved distinctions among closely related lineages. The results indicate that the rpoB gene provides a useful additional marker for phytoplasma classification that should facilitate studies of disease aetiology and epidemiology.

scholarly journals ‘Candidatus Phytoplasma sudamericanum’, a novel taxon, and strain PassWB-Br4, a new subgroup 16SrIII-V phytoplasma, from diseased passion fruit (Passiflora edulis f. flavicarpa Deg.)

2012 ◽  
Vol 62 (Pt_4) ◽  
pp. 984-989 ◽  
Author(s):  
Robert E. Davis ◽  
Yan Zhao ◽  
Ellen L. Dally ◽  
Rasa Jomantiene ◽  
Ing-Ming Lee ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Passion Fruit ◽  
Rrna Gene ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
Sequence Alignments ◽  
Passiflora Edulis ◽  
Content Type ◽  
Link Type

Symptoms of abnormal proliferation of shoots resulting in formation of witches’-broom growths were observed on diseased plants of passion fruit (Passiflora edulis f. flavicarpa Deg.) in Brazil. RFLP analysis of 16S rRNA gene sequences amplified in PCRs containing template DNAs extracted from diseased plants collected in Bonito (Pernambuco) and Viçosa (Minas Gerais) Brazil, indicated that such symptoms were associated with infections by two mutually distinct phytoplasmas. One phytoplasma, PassWB-Br4 from Bonito, represents a new subgroup, 16SrIII-V, in the X-disease phytoplasma group (‘Candidatus Phytoplasma pruni’-related strains). The second phytoplasma, PassWB-Br3 from Viçosa, represents a previously undescribed subgroup in group 16SrVI. Phylogenetic analyses of 16S rRNA gene sequences were consistent with the hypothesis that strain PassWB-Br3 is distinct from previously described ‘Ca. Phytoplasma ’ species. Nucleotide sequence alignments revealed that strain PassWB-Br3 shared less than 97.5 % 16S rRNA gene sequence similarity with previously described ‘Ca. Phytoplasma ’ species. The unique properties of its DNA, in addition to natural host and geographical occurrence, support the recognition of strain PassWB-Br3 as a representative of a novel taxon, ‘Candidatus Phytoplasma sudamericanum’.

Rhizobium halophytocola sp. nov., isolated from the root of a coastal dune plant

2012 ◽  
Vol 62 (Pt_8) ◽  
pp. 1997-2003 ◽  
Author(s):  
Fehmida Bibi ◽  
Eu Jin Chung ◽  
Ajmal Khan ◽  
Che Ok Jeon ◽  
Young Ryun Chung
Keyword(s):  
Phylogenetic Analysis ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Type Species ◽  
Coastal Dune ◽  
Rrna Gene ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
Content Type ◽  
Link Type

During a study of endophytic bacteria from coastal dune plants, a bacterial strain, designated YC6881T, was isolated from the root of Rosa rugosa collected from the coastal dune areas of Namhae Island, Korea. The bacterium was found to be Gram-staining-negative, motile, halophilic and heterotrophic with a single polar flagellum. Strain YC6881T grew at temperatures of 4–37 °C (optimum, 28–32 °C), at pH 6.0–9.0 (optimum, pH 7.0–8.0), and at NaCl concentrations in the range of 0–7.5 % (w/v) (optimum, 4–5 % NaCl). Strain YC6881T was catalase- and oxidase-positive and negative for nitrate reduction. According to phylogenetic analysis using 16S rRNA gene sequences, strain YC6881T belonged to the genus Rhizobium and showed the highest 16S rRNA gene sequence similarity of 96.9 % to Rhizobium rosettiformans , followed by Rhizobium borbori (96.3 %), Rhizobium radiobacter (96.1 %), Rhizobium daejeonense (95.9 %), Rhizobium larrymoorei (95.6 %) and Rhizobium giardinii (95.4 %). Phylogenetic analysis of strain YC6881T by recA, atpD, glnII and 16S–23S intergenic spacer (IGS) sequences all confirmed the phylogenetic arrangements obtained by using 16S rRNA gene sequences. Cross-nodulation tests showed that strain YC6881T was a symbiotic bacterium that nodulated Vigna unguiculata and Pisum sativum. The major components of the cellular fatty acids were C18 : 1ω7c (53.7 %), C19 : 0 cyclo ω8c (12.6 %) and C12 : 0 (8.1 %). The DNA G+C content was 52.8 mol%. Phenotypic and physiological tests with respect to carbon source utilization, antibiotic resistance, growth conditions, phylogenetic analyses of housekeeping genes recA, atpD and glnII, and fatty acid composition could be used to discriminate strain YC6881T from other species of the genus Rhizobium in the same sublineage. Based on the results obtained in this study, strain YC6881T is considered to represent a novel species of the genus Rhizobium , for which the name Rhizobium halophytocola sp. nov. is proposed. The type strain is YC6881T ( = KACC 13775T = DSM 21600T).

scholarly journals Poritiphilus flavus gen. nov., sp. nov., a member of the family Flavobacteriaceae isolated from coral Porites lutea

2020 ◽  
Vol 70 (11) ◽  
pp. 5620-5626 ◽  
Author(s):  
Guanghua Wang ◽  
Shuailiang Xu ◽  
Ge Dang ◽  
Jianfeng Liu ◽  
Hongfei Su ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Polar Lipids ◽  
Rrna Gene ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
Porites Lutea ◽  
Content Type ◽  
Link Type ◽  
The Family

A novel Gram-stain-negative, non-endospore-forming, non-motile, aerobic bacterium (strain R33T) was isolated from coral Porites lutea and subjected to a polyphasic taxonomic study. The G+C content was 44.5 mol%. The only detected respiratory quinone was menaquinone 6 (MK-6). The major cellular fatty acids were iso-C15 : 0 and iso-C15 : 1 ω6c. The major polar lipids were phosphatidylethanolamine and two unidentified lipids. Global alignment based on 16S rRNA gene sequences indicated that strain R33T shares the highest sequence identity of 93.2 % with Muriicola marianensis A6B8T in the family Flavobacteriaceae . Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain R33T forms a distinct branch in a stable clade comprising strain R33T and members of the genera Muriicola , Robiginitalea , Eudoraea and Zeaxanthinibacter . The phylogenomic analysis also supported this 16S rRNA gene-based phylogenetic result. Comparative genomic analysis indicated that strain R33T is rich in AraC-type DNA-binding domain-containing protein-coding genes, which means the regulation of carbon utilization is very complex. Low 16S rRNA gene identity, different polar lipids and/or cellular fatty acid profiles could readily distinguish strain R33T from any validly published type strains. Therefore, strain R33T is suggested to represent a new species in a new genus, for which the name Poritiphilus flavus gen. nov., sp. nov. is proposed. The type strain is R33T (=MCCC 1K03853T=KCTC 72443T).

scholarly journals Correlation of the Abundance of Betaproteobacteria on Mineral Surfaces with Mineral Weathering in Forest Soils

2012 ◽  
Vol 78 (19) ◽  
pp. 7114-7119 ◽  
Author(s):  
C. Lepleux ◽  
M. P. Turpault ◽  
P. Oger ◽  
P. Frey-Klett ◽  
S. Uroz
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Forest Soils ◽  
Mineral Weathering ◽  
Rrna Gene ◽  
Mineral Surfaces ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
Content Type

ABSTRACTPyrosequencing-based analysis of 16S rRNA gene sequences revealed a significant correlation between apatite dissolution and the abundance of betaproteobacteria on apatite surfaces, suggesting a role for the bacteria belonging to this phylum in mineral weathering. Notably, the cultivation-dependent approach demonstrated that the most efficient mineral-weathering bacteria belonged to the betaproteobacterial genusBurhkolderia.

Algoriphagus pacificus sp. nov. and Algoriphagus oliviformis sp. nov., isolated from a mariculture fishpond

2021 ◽  
Vol 71 (7) ◽  
Author(s):  
Huibin Lu ◽  
Zhipeng Cai ◽  
Tongchu Deng ◽  
Youfeng Qian ◽  
Meiying Xu
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Type Strain ◽  
Sequence Similarity ◽  
Rrna Gene ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
Respiratory Quinone ◽  
Content Type ◽  
Link Type

Two Gram-stain-negative, catalase-positive, oxidase-negative, rod-shaped, non-flagellated, non-spore-forming and non-motile strains (YJ13CT and H41T) were isolated from a mariculture fishpond in PR China. Comparisons based on 16S rRNA gene sequences indicated that YJ13CT and H41T shared 16S rRNA gene sequences similarities between 92.6 and 99.2 % with species of the genus Algoriphagus . YJ13CT only shared 93.8 % 16S rRNA gene sequence similarity with H41T. The reconstructed phylogenetic and phylogenomic trees indicated that YJ13CT and H41T clustered closely with species of the genus Algoriphagus . The calculated pairwise orthologous average nucleotide identity with usearch (OrthoANIu) values between strains YJ13CT and H41T and other related strains were all less than 79.5 %. The OrthoANIu value between YJ13CT and H41T was only 69.9 %. MK-7 was the predominant respiratory quinone of YJ13CT and H41T and their major cellular fatty acids contained iso-C15 : 0, C16 : 1 ω7c and C17 : 1 ω9c. The polar lipids profiles of YJ13CT and H41T consisted of phosphatidylethanolamine and several kinds of unidentified lipids. Combining the above descriptions, strains YJ13CT and H41T represent two distinct novel species of the genus Algoriphagus , for which the names Algoriphagus pacificus sp. nov. (type strain YJ13CT=GDMCC 1.2178T=KCTC 82450T) and Algoriphagus oliviformis sp. nov. (type strain H41T=GDMCC 1.2179T=KCTC 82451T) are proposed.

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